Pump system

ABSTRACT

A prosthetic system includes a prosthetic foot having an upper foot element with a concave-forward facing portion and foot portion extending forwardly therefrom. An intermediate foot element is disposed below the upper foot element and has a front portion coupled to the foot portion of the upper foot element. A lower foot element is disposed below the intermediate foot element. A pump system is coupled to the prosthetic foot and comprises a pump mechanism including a housing defining a cavity, and a membrane situated in the cavity. The pump mechanism is movable between an original configuration and an expanded configuration. An arm member is connected to the pump mechanism and operatively coupled to the intermediate foot element. The arm member is arranged to move the pump mechanism toward at least the expanded configuration upon movement of the intermediate foot element relative to the upper foot element.

TECHNICAL FIELD

The disclosure relates to the field of prosthetic devices, and moreparticularly to a prosthetic device, system and pump mechanism forincreasing vacuum in a vacuum assisted suspension system.

BACKGROUND

An ongoing challenge in the development of prosthetic devices is theattachment of the prosthetic device to the residual limb of a user. Forprosthetic legs, it is often difficult to securely attach the prostheticleg to the residual leg without exerting too much or uneven pressure onthe residual limb. On the one hand, the lack of a secure attachment canadversely affect the user's ability to walk. On the other hand, animproper fit can cause sores, swelling and pain for the user.

One approach for overcoming this challenge has been the application of anegative pressure vacuum in a space between the limb (or a liner donnedon the limb) and a socket or receptacle coupled to the prosthetic limb.Two conventional ways to apply such a vacuum are by a mechanical pump oran electronic pump.

Mechanical pumps are often in-line systems that utilize the movement ofthe user to generate the negative pressure vacuum in the socket. Forexample, the force generated by contacting the ground during a user'swalking motion can be used to generate a vacuum in the socket space tohold the prosthesis to the user's limb. However, in utilizing the motionof the user, known pumps rely on complete compression of the pump toexpel air from the pump before the pump can be decompressed to generatethe vacuum. Because the impact and displacement of the pump is notconsistent and varies between users, the vacuum and thus attachmentbetween the residual limb and the socket can be unpredictable and/orinadequate, causing the user discomfort, grief and even injury.

Yet another drawback is that many known pumps are integrated into theprosthetic limb in such a way that any failure of the pump would greatlyimpair the user's ability to walk. Many of these pumps are also bulkyand significantly contribute to the weight of the prosthetic limb,imposing a significant weight burden on the user when walking.

There is a need for a prosthetic device, system, and pump mechanism thatprovides freedom of vacuum suspension for a prosthetic system. There isalso a call for a prosthetic device that provides a secure vacuumwithout losing suction and confidence to the user over a period of use.It is also desirable for prosthetic devices to draw a vacuum while beinglightweight and streamlined.

SUMMARY

Embodiments of the prosthetic system provide vacuum assisted suspensionby generating negative pressure inside a prosthetic socket worn over aresidual limb, and reducing sliding movement between the liner and thesocket. The function of the embodiments is automatic as it is activatedduring gait. The weight placed on the foot member of the prosthetic footexpands and compresses the foot member, which, in turn, expands a pumpmechanism that efficiently draws air out from the socket in each step,and expels it into the atmosphere during swing phase as the pumpmechanism returns to an original configuration.

The pump mechanism utilizes the action of the prosthetic foot to createnegative pressure inside the socket without substantially affecting thefunctionality of the prosthetic foot. It also does so without the use ofcomplicated and bulky components as in the prior art, resulting in moresecure and reliable elevated vacuum suspension. Furthermore, the pumpmechanism can be a separate add-on module to the prosthetic foot and canbe adapted to fit a number of different prosthetic feet, providingversatility.

According to an embodiment, the prosthetic system includes a prostheticfoot having an upper foot element with a concave-forward facing portionand foot portion extending forwardly therefrom. An intermediate footelement is disposed below the upper foot element and has a front portioncoupled to the foot portion of the upper foot element. A lower footelement is disposed below the intermediate foot element. A pump systemis coupled to the prosthetic foot and includes a pump mechanismincluding a housing defining a cavity, and a membrane situated in thecavity. The pump mechanism is movable between an original configurationin which the volume of a fluid chamber defined between the membrane andthe bottom of the cavity is zero or near-zero, and an expandedconfiguration in which the volume of the fluid chamber is increased. Anarm member is connected to the pump mechanism and operatively coupled tothe intermediate foot element.

Relative movement between the upper foot element and the intermediatefoot element can shift the pump mechanism between the original andexpanded configurations. For instance, as the prosthetic foot movesthrough mid-stance and/or toe-off, the intermediate foot element canmove toward the upper foot element, causing the intermediate footelement to apply an upward force on the arm member. This upward force onthe arm member forces the arm member and at least a portion of thehousing upwardly, pulling the membrane away from the housing and drivingthe pump mechanism toward the expanded configuration.

The increase in volume of the fluid chamber creates a vacuum in the pumpmechanism. Movement of the intermediate foot element toward the upperfoot element thus automatically creates a vacuum in the pump mechanismwithout the use of fixed frame components that add detrimental weightand bulk to the prosthetic foot as in the prior art. It can also do sowithout engaging the heel of the prosthetic foot, increasing itsversatility.

At the end of the stance phase or when the weight of the user is removedfrom the prosthetic foot, the prosthetic foot returns to its restingposition. The inherent properties of the material of the pump mechanismcan help move the pump mechanism back toward its original configuration,decreasing the volume of the fluid chamber to a zero or near-zerovolume. During the return of the membrane toward the housing, the pumpmechanism expels fluid in the fluid chamber out of the pump mechanism.Because the pump mechanism returns to its original configuration of zeroor near-zero volume in the fluid chamber at the beginning or end of eachgait cycle, all fluid drawn into the pump mechanism is automaticallyexpelled.

According to a variation, the arm member is defined by the housing andis selectively engageable with an upper surface of the intermediate footelement. The arm member can comprise an elongate member having a rigidconfiguration that extends downwardly from the housing through anopening defined in the upper foot element toward the intermediate footelement. This advantageously helps the prosthetic system maintain alow-profile configuration because the arm member is routed through theprosthetic foot rather than around the prosthetic foot. It alsobeneficially helps protect the arm member from inadvertent contact withexternal objects because a length of the arm member is entirelysurrounded by the upper foot element, increasing the durability of thepump system.

According to a variation, the arm member defines a width orcross-sectional area increasing in a direction toward the intermediatefoot element, providing a more solid connection between the arm memberand the intermediate foot element.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood regarding the followingdescription, appended claims, and accompanying drawings.

FIG. 1 shows a prosthetic system with a pump system according to anembodiment.

FIG. 2A shows a sectional view of the prosthetic system in FIG. 1 in afirst configuration.

FIG. 2B shows a sectional view of the prosthetic system in FIG. 1 in asecond configuration.

FIG. 3 shows a prosthetic system with a pump system according to anotherembodiment.

FIG. 4 shows a prosthetic system with a pump system according to anotherembodiment.

FIG. 5 shows an exploded view of the pump system in FIG. 4.

FIG. 6 shows another exploded view of the pump system in FIG. 4.

FIG. 7 shows a prosthetic system with a pump system according to anotherembodiment.

FIG. 8 shows the pump system in FIG. 1 removed from the prosthetic foot.

FIG. 9 shows a prosthetic system with a pump system according to anotherembodiment.

FIG. 10 shows a sectional view of the prosthetic system in FIG. 9.

FIG. 11 shows a prosthetic system with a pump system according toanother embodiment.

FIG. 12 shows a sectional view of the prosthetic system in FIG. 11 in afirst position.

FIG. 13 shows a sectional view of the prosthetic system in FIG. 12 in asecond position.

FIG. 14 shows a prosthetic system with a pump system according toanother embodiment.

FIG. 15 shows a prosthetic system with a pump system according toanother embodiment.

FIG. 16 shows a prosthetic system with a pump system according toanother embodiment.

FIG. 17 shows the pump system of FIG. 16 removed from the prostheticsystem.

FIG. 18 shows a front view of the prosthetic system and pump system ofFIG. 16.

FIG. 19 shows a cross section view of a pump mechanism according toanother embodiment.

FIG. 20 shows a partial exploded view of the pump mechanism in FIG. 19.

FIG. 21 shows a pump mechanism according to another embodiment.

FIG. 22 shows a cross section view of the pump mechanism in FIG. 21.

FIG. 23 shows a partial exploded view of the pump mechanism in FIG. 21.

FIG. 24 shows a pump mechanism according to another embodiment.

FIG. 25 shows a pump mechanism according to another embodiment.

FIG. 26 shows a cross section view of the pump mechanism in FIG. 25.

FIG. 27 shows the base member in FIG. 25 removed from the pumpmechanism.

FIG. 28 shows a partial view of a pump mechanism according to anotherembodiment.

DETAILED DESCRIPTION OF THE DISCLOSURE

It will be understood that, unless a term is expressly defined in thisdisclosure to possess a described meaning, there is no intent to limitthe meaning of such term, either expressly or indirectly, beyond itsplain or ordinary meaning.

Any element in a claim that does not explicitly state “means for”performing a specified function, or “step for” performing a specificfunction, is not to be interpreted as a “means” or “step” clause asspecified in 35 U.S.C. §112, paragraph 6.

The embodiments of a prosthetic system will be described which form partof a vacuum system. A vacuum pump mechanism having a fluid connectionwith a socket assists in creating a vacuum between a residual limb andthe socket by pumping fluid out of the socket. The fluid is pumped outof the socket when the user puts his weight on a prosthetic foot such asupon heel strike, mid-stance and/or toe-off. The user's weight on theprosthetic foot can cause the pump mechanism to increase the volume of afluid chamber in the pump mechanism. The increase in volume of the pumpmechanism draws in fluid from the vacuum space between the residual limband the socket of a prosthetic limb. In this manner, the pump mechanismdecreases the air pressure within the vacuum space causing a vacuumeffect.

After the weight is removed, and/or shifted on the prosthetic foot, thevolume of the fluid chamber in the pump mechanism is automaticallydecreased. The connection between the vacuum space and the pump may havea one-way valve assembly, so all of the air within the volume of thepump is expelled out of an outlet to another space or to atmosphere. Theoutlet can be provided with a one-way valve assembly so the vacuum spaceis the only source of air.

The vacuum suspension system of the present disclosure produces a vacuumeffect in a prosthetic socket that is advantageous over prior artdevices that require compression of the pump to expel air before thepump can be decompressed to draw in air. The present disclosure alsoachieves smaller fluctuations in air pressure than the prior artsystems, so the difference between the greatest pressure and lowestpressure in the vacuum space of the socket is less.

The efficiency of the pump mechanism is determined at least in part byhow effectively the volume of the fluid chamber is reduced. Since thepump mechanism begins at and returns to the original state of zero ornear-zero volume at the beginning or end of each cycle in someembodiments, the volume of the fluid chamber is determined by the forceapplied to the pump, not by a full compression and recompression cycleas in the prior art. In addition, all fluid drawn into the pumpmechanism is expelled afterwards, fully utilizing the volume of thefluid chamber.

The vacuum suspension system also reduces volume fluctuations of theresidual limb and allows for increased proprioception and reducedpistoning since there is a better attachment between the socket and theresidual limb. It may also be beneficial to produce hypobaric pressurebelow a certain level in the socket. This may be achieved using asealing membrane or seal component between the residual limb and thesocket, instead of the conventional sealing method of using a sleeve toform an airtight connection between the residual limb and the proximalend of the socket. The sealing membrane may be on a prosthetic liner asdescribed in U.S. Pat. No. 8,034,120 incorporated by reference andbelonging to the assignee of this disclosure.

The benefit of using a liner having a seal or seal component reduces thevolume of air to be drawn out of the socket and therefore, a bettersuspension may be achieved in a shorter time period. Using a siliconeliner with integrated seal also provides the added benefit that thehypobaric region is not directly applied to the skin.

The vacuum pump mechanisms in the embodiments of the prosthetic systemdescribed are generally described as a pump mechanism and may includeany suitable type of pump mechanism. For instance, the pump mechanismmay be a pump as described in U.S. patent application Ser. No.14/747,788 incorporated by reference and belonging to the assignee ofthis disclosure. A piston-type pump may be used in the embodiments inplace of a membrane-type pump. A bladder-type pump may also be used inthe embodiments in place of a membrane-type pump, and a skilled personwould understand that the pump mechanisms described may also be usedwith a bladder-type pump and vice versa.

A bladder-type pump has an interior fluid chamber surrounded by anairtight material. When the interior chamber is expanded, the opposingwalls are moved away from each other by extending at least one side wallof the pump. The side walls of the bladder-type pump may have anaccordion-like shape or be formed of a polymeric material which allowsfor the increase in distance between the opposing walls.

A membrane-type pump has at least one wall of flexible material and asecond opposing wall which may be rigid or flexible. The edges of thetwo walls are attached to each other such that when a force applies tothe pump to expand the interior fluid chamber, the force deforms atleast the flexible wall, and the flexible wall arcs outward to form aninterior fluid chamber. To allow for deformation, the flexible wall maybe made of a polymeric material including elastomeric material such asrubber or plastic.

The bladder-type pump and membrane-type pump are arranged so that whenno force applies to the pump or no weight is placed on the prostheticsystem the volume of the interior fluid chamber is zero or near-zero.The pumps described and shown have a cylindrical shape. A skilled personwould understand that the pumps may have a variety of shapes, forexample, a diamond, rectangular, or triangular shape.

The specific embodiments of the prosthetic system will now be describedregarding the figures.

FIGS. 1-2 show an embodiment of a prosthetic system 5 comprising a pumpsystem 3 and a prosthetic foot 4. As seen in FIG. 1, the prosthetic foot4 includes an ankle portion 6. The ankle portion 6 can include a firstconnection portion 8 such as a pyramid connector. The first connectionportion 8 can attach to a stump on user, to another prosthetic system,or to any other appropriate object. It will be understood that the firstconnection 8 can include attachment features other than a pyramidconnector, such as a threaded hole or screw, a latch, a magnetic member,tube clamp, or other features. The ankle portion 6 can additionallyinclude second and third connection portions 10, 12. Optionally, theankle portion 6 can include or define a cover. The cover can protectvarious components of the prosthetic foot 4 such as electronics or othercomponents.

The ankle portion 6 can connect to an upper foot element 14 at the thirdconnection point 12. The upper foot element 14 can be substantiallyplate-like and can have a generally rectangular cross-section along itslength.

The third connection point 12 can provide a rotatable connection,although non-rotatable connections can also be used. In someembodiments, the rotation can be provided about an axle firmly mountedto the ankle portion 6, about which the upper foot element 14 canrotate. In other embodiments, the upper foot element 14 can be fixed tothe axle, and relative rotation can be allowed between the axle andankle portion 6. An attachment portion 15 can be disposed at theproximal end of the upper foot element 14. The attachment portion 15 caninclude or define a bushing or opening through which the axle extends.The attachment portion 15 can be integral to the proximal end of theupper foot element 14 or a separate structure.

The upper foot element 14 can be formed from a sufficiently flexiblematerial such as carbon fiber. The upper foot element 14 can besubstantially inelastic, so as to provide a rigid connection. It will beunderstood that the lower foot element and intermediate foot element(described below) can be formed of similar materials and have similarconnections as the upper foot element 14.

The upper foot element 14 can be formed into a shape arranged to providea desired flexibility or rigidity. As seen, the upper foot element 14can include a concave-forward portion 18 at or near the attachmentportion 15, although other shapes are also possible such as an L-shapeor J-shape. The upper foot element 14 can extend from the lower portionof the concave-forward portion 18 into a foot portion 20. The footportion 20 can further include a slit that extends longitudinally toseparate the foot portion 20 into two or more foot members that can flexindependently. In other embodiments, the foot portion 20 can bemonolithic without any slits.

The ankle portion 6 can connect to a connection unit 22 at the secondconnection portion 10. Like the third connection portion 12, the secondconnection portion 10 can be rotatable or non-rotatable. In someembodiments, the third connection portion 12 is in front of the ankleportion 6, and the second connection portion 10 is in a rear portion ofthe ankle portion 6. The connection unit 22 is located at a rear portionof the prosthetic foot 4. However, in other embodiments, the connectionunit 22 can be positioned in a front portion of the prosthetic foot.

The connection unit 22 can be in a variety of forms such as a connectionmember, an actuator, a rod connector, a rigid member, or a pistoncylinder. The connection unit 22 can be operated in a variety of ways,as described by example, in U.S. Pat. No. 7,896,927 and U.S. patentapplication Ser. No. 12/816,968, each of which is incorporated herein byreference in its entirety.

The connection unit 22 is depicted as connecting to an intermediate footelement 24 at a fourth connection portion 26. The fourth connectionportion 26 can be rotatable or non-rotatable. The intermediate footelement 24 can include or define a bushing or opening through which anaxle extends to provide a rotatable connection or pivot axis between theintermediate foot element 24 and the connection unit 22. Theintermediate foot element 24 can be substantially plate-like and canhave a generally rectangular cross-section along its length.

The intermediate foot element 24 can extend into a foot portion in amanner similar to the foot portion 20 of the upper foot element 14. Theintermediate foot element 24 can include a slit similar to the slit ofthe upper foot element 14. The intermediate foot element 24 is disposedbelow the upper foot element 14, and extends tangentially forward andtoward the upper foot element 14 to abut the upper foot element 14 alongthe foot portion 20 of the upper foot element 14. Although the upper andintermediate foot elements 14, 24 are depicted as ending atapproximately the same point, in some embodiments the upper foot element14 may extend further, or the intermediate foot element 24 may extendfurther.

The prosthetic foot 4 can further include a lower foot element 28. Thelower foot element 28 can extend from a heel portion 30 (e.g., acantilevered or free end) at a bottom and rear portion of the prostheticfoot 4. This heel portion 30, as shown, can be spaced from theconnection unit 22 and the intermediate foot element 24, curvingdownward toward and away from the connection unit 22. From the heelportion 30, the lower foot element 28 can extend to a toe portion 16 ofthe prosthetic foot 4, and can generally abut the foot portion of theintermediate foot element 24, as that member abuts the upper footelement 14. In the illustrated embodiment, the lower foot element 28extends forward beyond the upper foot element 14 and the intermediatefoot element 24. The lower foot element 28 can have a slit thatgenerally matches the slits in the upper and intermediate foot elements.

The prosthetic foot 4 can include one or more fastening members thatcouple two or more of the elements 14, 24, 28 to each other.Alternatively, two or more of the elements 14, 24, 28 can be coupledtogether with an adhesive or other suitable mechanism.

Attachment can be provided between the elements 14, 24, 28, for example,generally in a metatarsal region of the prosthetic foot 4. Where theelements 14, 24, 28 are not held together (e.g., by the fastenermembers) they can separate and act as distinct flexible members insteadof combining into a single flexible member where held together.

Optionally, the position of the one or more fastening members can beadjustable along the length of a slit defined in one or more of theelements 14, 24, 28. Thus, if the fastener member is moved forward, theelements 14, 24, 28 are held together over a shorter range, allowingmore separation between them, and thus greater flexibility (e.g., thelever arm of the intermediate foot element 24 is relatively longer,resulting in greater flexibility of the prosthetic foot 4.)Alternatively, if the fastener member is moved rearward, the elements14, 24, 28 are held together over a longer range, reducing the allowedseparation and flexibility (e.g., the lever arm of the intermediate footelement 24 is relatively shorter, resulting in increased stiffness ofthe prosthetic foot 4). Advantageously, the one or more fastener membersmay be adjustable to vary the stiffness of the prosthetic foot 4.

In some embodiments, the flexibility and resistance of the elements 14,24, 28 can be altered by the connection unit 22 (independently of, or incombination with, the one or more fastening members). Thus, it will beunderstood that the flexibility and resistance of the elements 14, 24,28 can be altered manually and/or by an actuator.

In use, the prosthetic foot 4 can expand and compress. The prostheticfoot 4 is in expansion when the ankle portion 6 rotates in acounter-clockwise direction (e.g., the first connection portion 8 on theankle portion 6 rotates away from the toe portion 16 of the prostheticfoot 4) and the connection unit 22 pushes the rear portion of theintermediate foot element 24 away from the upper foot element 14,increasing a distance 34 defined between the intermediate foot element24 and the upper foot element 14. It will be appreciated that theprosthetic foot 4 can be in expansion independent of rotation of theankle portion 6. For instance, the connection unit 22 can be an actuatorthat pushes the rear portion of the intermediate foot element 24 awayfrom the upper foot element 14 to move the foot into expansion.

The prosthetic foot 4 is in compression when the ankle portion 6 rotatesin a clockwise direction (e.g., the first connection portion 8 on theankle portion 6 rotates toward the toe portion 16 of the prosthetic foot4) and the connection unit 22 pulls the rear portion of the intermediatefoot element 24 toward from the upper foot element 14, closing thedistance 34. It will also be appreciated that the prosthetic foot 4 canbe in compression independent of rotation of the ankle portion 6. Forinstance, the connection unit 22 can be an actuator that pulls the rearportion of the intermediate foot element 24 toward the upper footelement 14 to move the foot into compression. The prosthetic foot 4 maybe insertable into a foot cover 21 as seen in FIG. 2.

An example of the prosthetic foot 4 is described in greater detail inU.S. patent application Ser. No. 14/188,216, filed on Feb. 24, 2014, andcommercially available as the PROFLEX by Össur hf. This disclosure isincorporated by reference and belongs to the assignee of thisdisclosure.

In order to better understand the operation of the prosthetic foot 4, abasic discussion of the gait cycle is required. The gait cycle definesthe movement of the leg between successive heel contacts of the samefoot. The gait cycle has two phases: stance and swing. Of particularinterest is the stance phase which generally includes heel-strike orinitial contact, mid-stance, and toe-off.

It is during the stance phase that the mechanics of the prosthetic foot4 come into play. Upon heel strike, the prosthetic foot 4 is inexpansion, providing cushioning to the user. During mid-stance, at whichtime the weight of the user is transmitted through the prosthetic foot 4to a support surface, the prosthetic foot 4 moves from expansion intocompression. The prosthetic foot 4 remains in compression throughtoe-off until the weight of the user is removed from the prostheticfoot, at which time the prosthetic foot 4 returns to its restingposition.

The pump system 3 includes a pump mechanism 2 and a securing member 36.The pump mechanism 2 can be coupled to the prosthetic foot 4 at anysuitable location, but is shown coupled to the concave-forward portion18 located at or toward the proximal end of the upper foot element 14.The pump mechanism 2 can be made generally from carbon fiber and anelastomeric compound (e.g., a membrane) providing durable yetlightweight components. Prior art pump mechanisms are typically of heavymetal construction, which imposes a significant weight burden on theuser when ambulating.

The pump mechanism 2 is operably connected to the intermediate footelement 24 and the securing member 36 secured to the attachment portionof the upper foot element 14. As described in more detail below,relative movement between the securing member 36 and the intermediatefoot element 24 moves the pump mechanism 2 between an originalconfiguration and an expanded configuration.

As best seen in FIG. 2A, the pump mechanism 2 includes a housing 40containing two valve assemblies 42 (shown in FIG. 1), 44, a membrane 46,and a connector 48. The valve assemblies can include a one-way valve,also referred to as a check valve. A preferred type of one-way valveused is a duckbill valve. It should be appreciated however that othertypes of one-way valves are possible.

The valve assembly 42 is arranged to only allow fluid to enter the pumpmechanism 2. The valve assembly 42 can be in fluid communication withthe cavity of a prosthetic socket. When the volume of the pump mechanism2 increases, fluid (e.g., air) can be drawn out from the socket via thevalve assembly 42. The valve assembly 44 is arranged to only allow fluidto be expelled out of the pump mechanism 2, preferably to atmosphere.

The housing 40 can be coupled to the securing member 36 via at least onefastener 50 situated at a front portion of the housing 40 and securingmember 36. It should be appreciated that the pump mechanism 2 and/orpump system can be a separate add-on module to the prosthetic foot 4.For example, the pump mechanism 2 can be removably attached to thesecuring member 36 via the fastener 50 and the connector 48. Because thepump mechanism 2 is not integrated into the prosthetic foot 4, failureof the pump mechanism 2 advantageously would not affect the performanceof the prosthetic foot 4.

The housing 40 can have a rigid configuration. The housing 40 can definea main portion 52, a front portion 54, and a rear portion 64 oppositethe front portion 54. The main portion 52 can have any shape but isshown having a generally cylindrical shape. The front portion 54 canhave an elongate configuration and extend forwardly over an uppersurface of the securing member 36.

The housing 40 can have a width that tapers from the main portion 52 tothe front portion 54 such that the front portion 54 is narrower than themain portion 52. This advantageously can facilitate the pivoting and/orflexing of the housing 40 in the area of the front portion 54. Accordingto a variation, the bottom surface of the front portion 54 can include arocker-like curvature 55 that allows the housing 40 to rock back andforth as the pump mechanism 2 moves between original and expandedconfigurations described below.

The front portion 54 can define a hole arranged to receive a shaft ofthe fastener 50. The rear portion 64 of the housing 40 defines an armmember 38 arranged to move or drive the pump mechanism 2 toward at leastan expanded configuration (described below) upon movement of theintermediate foot element 24 relative to the upper foot element 14. Thearm member 38 extends generally downward from the main portion 52 andhas a lower end including an engagement surface 56 arranged toselectively engage with the upper surface of the intermediate footelement 24. The arm member 38 has a rigid configuration. The arm member38 is shown as a push member but can comprise any suitable member.

The bottom surface of the main portion 52 of the housing 40 defines acavity 58 that is provided with an undercut circumferential groove 60between an open end of the cavity 58 and a closed bottom 62 of thecavity 58. An outer radial edge portion of the membrane 46 can besituated in the circumferential groove 60 such that a seal is formedbetween the membrane 46 and the housing 40. Optionally, an adhesive canbe applied between the housing 40 and the outer radial edge portion ofthe membrane 46, increasing the sealing effect. The bottom 58 of thecavity 50 can define two openings which extend into the housing 40 toform internal passageways providing fluid communication between a fluidchamber defined below and the one-way valve assemblies 42, 44.

The pump mechanism 2 is movable between an original configuration inwhich the volume of a fluid chamber 64 defined between the top surfaceof the membrane 46 and the bottom 62 of the cavity is zero or near-zero(shown in FIG. 2A), and an expanded configuration in which the volume ofthe fluid chamber 64 is increased (shown in FIG. 2B).

The bottom 62 of the cavity 58 can substantially complement the topsurface of the membrane 46 such that when no force is exerted on thepump mechanism 2 it is in the original configuration. Both the bottom 62of the cavity 58 and the top surface of the membrane 46 can be generallyflat.

When a force is exerted on the membrane 46 in a direction away from thehousing 40, the pump mechanism 2 moves toward the expanded configuration(shown in FIG. 2B) as the force pulls a portion of the membrane 46 awayfrom the bottom 62 of the cavity 58, causing deformation of the membrane46 and an increase in volume of the fluid chamber 64. This increase involume of the fluid chamber 64 can draw fluid into the fluid chamber 64from the socket through the one-way valve assembly 42. The housing 40may be formed of metal such as stainless steel, carbon fiber, or plasticor any other material which would provide sufficient strength to resistdeformation when pulled away from the membrane 46.

Once the force is removed from the membrane 46, the pump mechanism 2returns toward its original configuration as the membrane 46 returnstoward the bottom 62 of the cavity 58 and fluid within the fluid chamber64 is expelled out of the one-way valve assembly 44. The membrane 46 canbe elastomeric and can use at least in part its material properties tonaturally or elastically return to its original position on the bottom62 of the cavity 58.

The membrane 46 may have any desired shape, but is shown having agenerally circular or elliptical shape. The membrane 46 can beoperatively attached at or near its center point to the securing member36 while the outer radial edge portion of the membrane 46 is attached tothe housing 40 such that when the membrane 46 is pulled away from thehousing 40 a pocket forms in a middle area of the membrane 46 due to thedeformation of the membrane 46. The formation of the pocket increasesthe volume of the fluid chamber 64. The pump mechanism 2 thus uses acompliant membrane to create suction.

The connector 48 can have an upper radial flange 66 embedded in themembrane 46, a lower radial flange 68 below the membrane 46, and a shaftportion 70 extending between the upper flange 66 and the lower flange68. Optionally, the connector 48 may be of a two-piece construction suchthat the lower flange 68 can be threadedly removed from the upper flange66 in the membrane 46. The connector 48 may be formed of metal, plastic,or any other suitable material. The upper flange 66 may extendsubstantially into the membrane 46 or may be formed of a material thatis part of the membrane 46 (e.g., a flexible metal member).

The securing member 36 can be a plate defining a rear portion 72, afront portion 74, and a middle portion 76 extending between the rearportion 72 and the front portion 74. The rear portion 72 defines a partextending generally upward that is attached to the attachment portion 15of the upper foot element 14. The securing member 36 can be connected tothe upper foot element 14 in any suitable manner but is shown attachedvia a fastener 78. The rear portion 72 can define an aperture forreceiving the fastener 78 to connect the securing member 36 to the upperfoot element 14.

The middle portion 76 and front portion 74 extend forwardly from therear portion 72 above the foot portion 20 of the upper foot element 14.The securing member 36 can have a flexible, rigid, and/or semi-rigidconfiguration.

The securing member 36 can be operatively connected to the membrane 46via the connector 48. The middle portion 76 of the securing member 36can define a connector opening 80. The connector opening 80 can have adiameter that is oversized relative to the lower flange 68 of theconnector 48.

To attach the pump mechanism 2 and connector 48 to the securing member36, the shaft portion 70 and lower flange 68 of the connector 48 can beinserted through the connector opening 80. The connector 46 with thepump mechanism 2 can then be slid toward the rear portion 72 until theupper surface of the lower flange 68 engages a lower surface of thesecuring member 36 along the rearward side of the opening 80, properlypositioning the pump mechanism 2 on the securing member and a portion ofthe lower flange 68 below the securing member 36. In this position, thehousing 40 can be coupled to the securing member via the fastener 50,securing the membrane 46 to the securing member 36 via the connector 46.Through the structure of the connector 46 and the securing member 36,the securing member 36 and/or the pump mechanism 2 has the benefit ofbeing easily and quickly removed and/or replaced from the prostheticfoot 4.

The securing member 36 defines a first through hole 81 and the upperfoot element 14 defines a second through hole 83 through which the armmember 38 extends from the main portion 52 of the housing 40 toward theupper surface of the intermediate foot element 24. As such, portions ofthe arm member 38 are entirely surrounded by the upper foot element 14or the securing member 36. This advantageously helps the prostheticsystem maintain a low-profile configuration by routing the arm member 38through the prosthetic foot 4 rather than around the prosthetic foot 4.It also beneficially helps protect the arm member 38 from inadvertentcontact with external objects.

The securing member 36 can be formed of carbon fiber or another suitablematerial. The location, shape, and/or length of the opening 80 and/orfirst and second through holes 81, 83 can be adjusted based on the sizeof the prosthetic foot 4 and/or pump mechanism 2, the weight of theuser, and/or other factors.

FIGS. 1 and 2A show the prosthetic foot in its resting position. Whenthe prosthetic foot 4 is in the resting position, the engagement surface56 on the arm member 58 can be lightly resting on or a small distanceabove the upper surface of the intermediate foot element 24, and thepump mechanism 2 is in its original configuration.

Upon heel strike, the prosthetic foot 4 moves into expansion, which, inturn, causes the connection unit 22 to push the intermediate footelement 24 away from the engagement surface 56 of the arm member 38.With the prosthetic foot 4 in expansion, the pump mechanism remains inits original configuration.

As the prosthetic foot 4 moves from heel strike through mid-stanceand/or toe-off, the prosthetic foot 4 moves into compression. Incompression, the connection unit 22 pulls the intermediate foot element24 toward the upper foot element 14, closing the distance 34 andapplying an upward force on the engagement surface 56 of the arm member38 as shown in FIG. 2B.

Referring still to FIG. 2B, the arm member 38 transfers the upward forceon the engagement surface 56 to the housing 40, forcing the back portion64 of the housing 40 away from the securing member 36. This causes thehousing 40 to pivot and/or flex around the front portion of the housing40 attached to the securing member 36, which, in turn, pulls themembrane 46 away from the housing 40, driving the pump mechanism 2toward the expanded configuration. More particularly, the arm member 38drives the housing 40 away from the membrane 46 to deform the membrane46 between the securing member 36 and the housing 40, increasing thevolume of the fluid chamber 64.

This increase in volume of the fluid chamber 64 creates a vacuum in thepump mechanism 2, pulling fluid into the pump mechanism 2 through theone-way valve assembly 42. Compression of the prosthetic foot 4 thusautomatically creates a vacuum in the pump mechanism 2. This isadvantageous over prior art prosthetic devices that require compressionof the pump to expel air before the pump can be decompressed to draw inair. Further, because the pump mechanism 2 does not need to be firstcompressed before it can create a vacuum upon decompression, the pumpmechanism 2 can achieve smaller fluctuations in air pressure than theprior art devices, so the difference between the greatest pressure andlowest pressure in the vacuum space of the socket is less than comparedto the prior art devices.

At the end of the stance phase or when the weight of the user is removedfrom the prosthetic foot 4, the prosthetic foot 4 returns to its restingposition and the inherent properties of the housing 40 and/or membrane46 can help move the pump mechanism 2 back toward its originalconfiguration and decrease the volume of the fluid chamber 64 to a zeroor near zero volume.

During the return of the membrane 46 toward the housing 40, the pumpmechanism 2 expels fluid in the fluid chamber 64 out of the one-wayvalve assembly 44. Because the pump mechanism 2 returns to its originalconfiguration of zero or near-zero volume in the fluid chamber 64 at thebeginning or end of each gait cycle, all fluid drawn into the pumpmechanism 2 is automatically expelled. This is advantageous becauseprior art devices rely on complete compression of the pump in expellingair in each gait cycle to use the pump to its maximum capacity. It isdifficult for complete compression to occur in every cycle using thegait of a user as the actuating force since the impact and displacementof the pump is not consistent and varies between users.

To meet the stiffness/flexibility, strength, and weight requirementsneeded for use on the prosthetic foot, the securing member 36 and/or armmember 38 can be made of a durable but flexible material such as carbonfiber cloth, unidirectional composites, plastic, or metal.

FIG. 3 includes a prosthetic system 5 comprising a vacuum suspensionsystem 400 including the pump system 3 and the prosthetic foot 4. Thevacuum suspension system 400 has a socket 401, a liner preferablyincluding a seal component, a valve assembly 403, a tube 405 connectingthe pump mechanism 2 to the socket 401, and the prosthetic foot 4. Thesocket 401 defines an interior space, and an interior wall delimitingthe interior space. The vacuum suspension system 400 may also employ anadaptor system 407. Alternatively, the adaptor system 407 can bereplaced with a shock and/or rotation module.

The vacuum suspension system 400 provides improved proprioception andvolume control since there is better attachment between the socket 401and the residual limb. The vacuum suspension system 400 includes thepump system 3 having the pump mechanism 2 and the securing member 36, asdescribed above, which provide a vacuum assisted suspension bygenerating a negative pressure (vacuum) inside the socket 401.

The function of the vacuum suspension system 400 can be fully automatic.During mid-stance and/or toe-off, compression of the prosthetic foot 4expands the pump mechanism 2 to efficiently draw fluid out of the socket401 in each step. During the swing phase, decompression of theprosthetic foot 4 permits the pump mechanism 2 to return to its originalposition, expelling the fluid drawn from the socket 401 to atmosphere.The pump mechanism 2 thus can create a negative pressure inside thesocket 401, resulting in a secure and reliable elevated vacuumsuspension that provides an intimate suspension as the negative pressureformed inside of the socket 401 holds the liner and the residual limbfirmly to the socket wall.

Another embodiment of a prosthetic system 85 is shown in FIGS. 4-6. Thisembodiment can be similar to the first embodiment illustrated in FIGS.1-3. As seen in FIG. 4, the prosthetic system includes the prostheticfoot 4 and a pump system 81. The pump system 81 includes a pumpmechanism 82 and a securing member 88. The pump mechanism 82 is attachedto the securing member 88 and situated above the upper foot element 14of the prosthetic foot 4. The pump mechanism 82 is operably connected tothe intermediate foot element 24 via an arm member and the securingmember 88 is secured to the attachment portion on the upper foot element14.

Referring to FIGS. 5 and 6, the pump mechanism 82 includes a housing 90containing two one-way valve assemblies 92, 94, a membrane 96 (shown inFIG. 4), and a connector 98 (shown in FIG. 4). The valve assembly 92only allows fluid to enter the pump mechanism 82 which can be in fluidcommunication with the cavity of a socket. The valve assembly 94 onlyallows fluid to be expelled out of the pump mechanism 82, preferably toatmosphere. The connector 98 can include an upper radial flange embeddedin the membrane 96, a lower radial flange below the membrane 96, and ashaft portion extending between the upper and lower flanges.

The housing 90 can be coupled to the securing member 88 via at least onefastener 102 situated at a front portion of the housing 90 and thesecuring member 88. The housing 90 can have a rigid configuration. Thehousing 90 defines a main portion 104, a front portion 106, and a rearportion 108 opposite the front portion 106. The front portion 106 canhave an elongate configuration and extend forwardly over an uppersurface of the securing member 88. The rear portion 108 of the housing90 can define an arm member 110 extending generally downward from thehousing 90 and arranged to move or drive the pump mechanism 82 toward atleast an expanded configuration (described below) upon movement of theintermediate foot element 24 relative to the upper foot element 14. Thearm member 110 can comprise a push member having a lower end defining anengagement surface 112 arranged to engage with the upper surface of theintermediate foot element 24. The arm member 110 can have a rigidconfiguration.

Similar to the pump mechanism 2, the pump mechanism 82 relies upondeformation of the membrane 96 to move between an original configurationin which the volume of a fluid chamber defined between the top surfaceof the membrane 96 and the bottom of the housing 90 is zero ornear-zero, and an expanded configuration in which the volume of thefluid chamber is increased. The housing 90 is arranged to surround theouter radial edge portion of the membrane 96 and creates a seal with themembrane 96. The bottom surface of the housing 90 can define a pair ofopenings which extend into the housing 90 to form internal passagewaysto provide fluid communication between the fluid chamber and the twoone-way valve assemblies 92, 94.

The securing member 88 can comprise a plate member 114 and a backingportion 116. Optionally, the backing portion 116 and the plate member114 can be made of different materials. For instance, the plate member114 can be made of carbon fiber cloth and the backing portion 116 can bemade of metal, plastic, or another suitable material, facilitatingproduction. Moreover, because the securing member 88 includes a two partconstruction, the length, curvature, and/or shape of the plate member114 can be advantageously adjustable or customizable without having toreplace the entire securing member 88.

The plate member 114 can include a rear portion 117, a front portion118, and a middle portion 120 extending between the rear and frontportions 117, 118. The plate member 114 can be formed of carbon fibercloth or another suitable material. The plate member 114 can have awidth that tapers from the middle portion 120 toward the front portion116 such that the front portion 118 is narrower than the middle portion120.

The front portion 118 can define an aperture 122 for receiving thefastener 102 to connect the plate member 114 to the front portion of thehousing 90. The middle portion 120 defines an aperture 124 forconnecting the plate member 114 to the connector 98. A slot or notch 126is formed in the terminal edge of the rear portion 116 that allows thearm member 110 to extend through the plate member 114. The rear portion116 can define a pair of apertures 128 on opposing sides of the notch126.

The backing portion 116 includes a base 130 and a back member 132. Theupper surface of the base 130 defines a seat 134 arranged to accommodatethe rear portion 116 of the plate member 114 when the plate member 114is attached to the backing portion 116. This beneficially limits orprevents the plate member 114 from sliding sideways off of the backingportion 116. A slot or notch 136 is defined in the base 130 thatgenerally corresponds to the notch 126 in the plate member 114, allowingthe arm member 110 to extend through the base 130. The base 130 furtherdefines a pair of apertures 138 in the seat 134 corresponding to theapertures 128 on the plate member 114 for receiving one or morefasteners to attach the plate member 114 to the backing portion 116.

The back member 132 can extend generally upward from a rear end of thebase 130. The back member 132 can be generally perpendicular to the base130 or oblique relative to the base 130. The back member 132 can definean aperture 140 for receiving a fastener to connect the backing portion116 to the upper foot element 14 and/or the attachment portion 15 (shownin FIG. 4) of the foot 4.

The rear surface of the back member 132 can generally complement thefront surface of the attachment portion 15. According to a variation,the rear surface of the back member 132 can define one or more alignmentfeatures including a pair of pin members 142 arranged to be receivedwithin a pair of corresponding openings defined in the attachmentportion. These advantageously help align the fastener aperture 140 onthe back member 132 and a fastener aperture on the attachment portion15, facilitating connection and/or removal of the securing member fromthe foot.

Another embodiment of a prosthetic system 143 is shown in FIGS. 7 and 8.This embodiment can be similar to the previously described embodiments.The prosthetic system 143 includes a prosthetic foot 144 and a pumpsystem 145. The prosthetic foot 144 can be similar to other embodimentsof the prosthetic foot. For instance, it can include an ankle portion148 and an upper foot element 150 coupled to the ankle portion 148 viaan attachment portion 180 (shown in FIG. 8). The attachment portion 180can include or define a bushing or opening 181 through which an axleextends.

An intermediate foot element 152 is disposed generally below the upperfoot element 150 and attached to the upper foot element 150 at a frontportion thereof. The prosthetic foot 144 can have a lower foot element154 disposed below the intermediate foot element 152. The lower footelement 154 extends rearwardly to a free end and extends forwardly to atoe portion of the foot 144. A connection unit 156 can extend betweenthe rear of the ankle portion 148 and the rear portion of theintermediate foot element 152. In use, the prosthetic foot 144 canexpand and compress.

The pump system 145 includes a pump mechanism 146 and a securing member158. The pump mechanism 146 is situated above the upper foot element 150and operably connected to the intermediate foot element 152 and thesecuring member 158 secured to the attachment portion 180 on the upperfoot element 150.

The pump mechanism 146 can be configured similarly to the previouslydescribed pump mechanisms. For instance, the pump mechanism 146 caninclude a housing 160 containing two one-way valve assemblies, amembrane, and a connector. One of the valve assemblies only allows fluidto enter the pump mechanism 146 which can be in fluid communication withthe cavity of a socket. The other valve assembly only allows fluid to beexpelled out of the pump mechanism 146, preferably to atmosphere. Theconnector can be attached to the membrane and the securing member 158and can exhibit any suitable configuration. For instance, the connectormay be a single fastener or screw, allowing the pump mechanism 146 toeasily retrofit on a prosthetic foot.

The pump mechanism 146 relies upon deformation of the membrane to movebetween an original configuration in which the volume of a fluid chamberdefined between an upper surface of the membrane and the bottom of thehousing 160 is zero or near-zero, and an expanded configuration in whichthe volume of the fluid chamber is increased. The housing 160 isarranged to surround the outer radial edge portion of the membrane andcreates a seal with the membrane. The bottom of the housing 160 candefine a pair of openings which extend into the housing 160 to forminternal passageways to provide fluid communication between the fluidchamber and the two one-way valve assemblies.

As best seen in FIG. 8, the securing member 158 can exhibit a two-partconstruction. The securing member 158 can include a plate member 160 anda backing portion 162. Optionally, the backing portion 162 and the platemember 160 can be made of different materials.

The plate member 160 can include a rear portion 164, a front portion166, and a middle portion 168 extending between the rear and frontportions. The plate member 160 can be formed of carbon fiber cloth oranother suitable material. The plate member 160 can have any suitableshape but is shown having a width that tapers from the middle portion168 toward the front portion 166 such that the front portion 166 isnarrower than the middle portion 168.

The middle portion 168 can define an aperture 170 for connecting thesecuring member 158 to the connector. A cutout 172 is defined in theplate member 160 at or near the rear portion 164 that allows an armmember of the pump mechanism 146 to extend through the plate member 160toward the intermediate foot element 152. The rear portion 164 candefine a connection tab 174 that extends generally upward from the platemember 160. The connection tab 174 can define an aperture for receivinga fastener 178 to connect the securing member 158 to the prosthetic foot144.

The backing portion 162 extends generally upright or obliquely relativeto the plate member 160. The backing portion 162 can define an internalcavity with an open bottom into which the connection tab 174 can beinserted. The backing portion 162 can also define an aperture 176 forreceiving the fastener 178. As such, the connection tab 174 of the platemember 160 can be inserted into the backing portion 162. The connectiontab 174 and the backing portion 162 can then be secured to theattachment portion 180 of the prosthetic foot 144 by inserting thefastener 178 through the apertures. This advantageously allows thesecuring member 158 to be directly attached to the prosthetic foot 144using a single fastener as opposed to multiple fasteners, facilitatingthe retrofit of a prosthetic foot with the pump system.

Another embodiment of a prosthetic system 183 is shown in FIGS. 9 and10. The prosthetic system comprises a pump system 182 and the prostheticfoot 4. The pump system 182 includes a pump mechanism 184 and a securingmember 186. The pump mechanism 184 is attached to the securing member186 and situated above the upper foot element 14. The pump mechanism 184is operably connected to the intermediate foot element 24 via an armmember 208 and the securing member 186 is secured to the attachmentportion 15 on the upper foot element 14. The prosthetic foot 4 may beinsertable into a foot cover 218 as seen in FIG. 10.

The pump mechanism 184 includes a housing 188 containing two one-wayvalves 190, 192, a membrane 194, and a connector 196. The valve assembly190 only allows fluid to enter the pump mechanism 184 and the valveassembly 192 only allows fluid to be expelled out of the pump mechanism184. The connector 196 can include an upper radial flange embedded inthe membrane 194, and a lower radial flange below the membrane 194, anda shaft portion extending between the upper and lower flanges.

The housing 188 can have a rigid configuration and can define a mainportion 198, a front portion 202, and a rear portion 204 opposite thefront portion 202. The front portion 202 can have an elongateconfiguration and extend forwardly and downwardly from the main portion198 to a front edge 206 arranged to engage the upper surface of theupper foot element 14.

The rear portion 204 can define the arm member 208. The arm member 208is arranged to drive or move the pump mechanism 184 toward at least anexpanded configuration (described below) upon engagement with theintermediate foot element 24 and movement of the intermediate footelement 24 relative to the upper foot element 14. The arm member 208 canbe any suitable mechanism but is shown comprising a push memberextending generally downward to a lower end defining an engagementsurface 210 arranged to engage with the upper surface of theintermediate foot element 24. The arm member 208 can have a rigidconfiguration.

Similar to the other pump mechanisms, the pump mechanism 184 relies upondeformation of the membrane 194 to move between an originalconfiguration in which the volume of a fluid chamber 195 defined betweenthe top surface of the membrane 194 and the bottom of the housing 188 iszero or near-zero, and an expanded configuration in which the volume ofthe fluid chamber is increased. The housing 188 is arranged to surroundthe outer radial edge portion of the membrane 194 and creates a sealwith the membrane 194. The bottom surface of the housing 188 can definea pair of openings which extend into the housing 188 to form internalpassageways, providing fluid communication between the fluid chamber andthe two one-way valve assemblies 190, 192.

The securing member 186 can be a plate defining a first part 214extending below a portion of the housing 188 and a second part 212extending generally upward from the first part and attached to theattachment portion 15 of the upper foot element 14. The first part 214of the securing member 186 can be connected to the housing 188 in anysuitable manner. For instance, the first part of the securing member 186can be bonded to the front portion of the housing 188. In otherembodiments, the first part 214 can secured to the housing 188 via theconnector 196 extending through an opening 216 defined in the first part214.

The securing member 186 can be connected to the attachment portion 15 inany suitable manner but is shown attached via a fastener. The secondpart 212 can define an aperture for receiving the fastener to connectthe securing member 186 to the attachment portion 15 or upper footelement 14.

When the prosthetic foot 4 is in its resting position, the front edge206 of the housing 188 is engaged with the upper surface of the upperfoot element 14 and the pump mechanism 184 is in its originalconfiguration. Upon heel strike, the prosthetic foot 4 moves intoexpansion, which, in turn, causes the connection unit 22 to push theintermediate foot element 24 away from the engagement surface 210 of thearm member 208. With the prosthetic foot 4 in expansion, the pumpmechanism remains in its original configuration.

As the prosthetic foot 4 moves from heel strike through mid-stanceand/or toe-off, the prosthetic foot moves into compression. Incompression, the connection unit 22 pulls the intermediate foot element24 toward the upper foot element 14, applying an upward force on theengagement surface 210 of the arm member 208.

This upward force drives the arm member 208 upward, forcing the rearportion 204 away from the securing member 186 and causing the housing188 to pivot around the connection between the securing member 186 andthe housing 188. This pulls the membrane 194 away from the housing 188,driving the pump mechanism 184 toward the expanded configuration. At theend of the stance phase or when the weight of the user is removed fromthe prosthetic foot 4, the prosthetic foot 4 returns to its restingposition and the inherent properties of the housing 188 and/or membrane194 help move the pump mechanism 184 back toward its originalconfiguration.

Another embodiment of a prosthetic system 223 comprising a pump system220 and the prosthetic foot 4 is shown in FIGS. 11-13. This embodimentcan be similar to the previously described embodiments except that thepump system has a different construction.

The pump system 220 includes a pump mechanism 222 and an arm member 224arranged to move or drive the pump mechanism 222 toward at least anexpanded configuration (described below) upon movement of theintermediate foot element 24 relative to the upper foot element 14. Thepump mechanism 222 includes a housing 226, at least one inlet valveassembly 228, at least one outlet valve assembly 230, a membrane 232(shown in FIG. 12), and a connector 234 (shown in FIG. 12). The pumpmechanism 222 relies upon of the membrane 232 to move between anoriginal configuration in which the volume of a fluid chamber 233defined between an upper surface of the membrane 232 and the bottom ofthe housing 226 is zero or near-zero, and an expanded configuration inwhich the volume of the fluid chamber 233 is increased.

The housing 226 can have a rigid configuration and defines a mainportion 236, and a rear portion 238 extending generally upwardly orobliquely from the main portion 236. The housing 226 can be coupled tothe attachment portion 15 via at least one fastener. A rear surface ofthe rear portion 238 can generally complement the front surface of theattachment portion 15. It should be appreciated that the pump mechanism222 can be a separate add-on module to the prosthetic foot 4. Becausethe pump mechanism 222 is not integrated into the prosthetic foot 4,failure of the pump mechanism 222 beneficially would not affect theperformance of the prosthetic foot 4.

The arm member 224 can be a plate located over the upper foot element14. A front portion 225 of the plate 224 is connected to the pumpmechanism 222 via the connector 234. For instance, the front portion 225of the plate 224 can define an aperture 243 (shown in Fig.12) forconnecting the plate 224 to the membrane 232 via the connector 234.

The plate 224 has two arms 240 which extend along each side of theprosthetic foot 4 from the plate 224 to the rear area of theintermediate foot element 24. Each arm 240 can include a rear portiondefining an engagement surface 242 arranged to engage with the rearportion of the intermediate foot element 24.

Similar to the other embodiments, the pump system 220 utilizes thedisplacement which occurs between the intermediate foot element 24 andthe upper foot element 14 during the gait cycle to move the pumpmechanism 222 between its original and expanded configurations.

FIG. 12 shows the prosthetic foot 4 in its resting position. Upon heelstrike, the prosthetic foot 4 moves into expansion, which, in turn,causes the connection unit 22 to push the intermediate member 24 awayfrom the engagement surface 242 of the plate 224. With the prostheticfoot 4 in expansion, the pump mechanism remains in its originalconfiguration.

As the prosthetic foot 4 moves from heel strike through mid-stanceand/or toe-off, the prosthetic foot 4 moves into compression as seen inFIG. 13. In compression, the connection unit 22 pulls the intermediatefoot element 24 toward the upper foot element 14, closing the distancetherebetween and applying an upward force on the engagement surface 242of the plate 224.

The plate 224 then transfers this upward force to the pump mechanism222, driving the pump mechanism 222 toward the expanded configuration.For instance, the upward force on the engagement surface 242 causes theplate 224 to pivot or rotate at or near the rear portion 238 of thehousing 226, rotating the front portion of the plate 224 attached to themembrane 232 away from the housing 226. This forces the pump mechanism222 toward the expanded configuration.

The pump mechanism 222 can be arranged at various points on the front ofthe prosthetic foot in combination with different angles of the arms 240to control the length of the displacement between the original andexpanded configurations.

Another embodiment of a prosthetic system 247 comprising a pump system246 and a prosthetic foot 248 is shown in FIG. 14. This embodiment canbe similar to the other embodiments. The prosthetic foot 248 can besimilar to other embodiments of the prosthetic foot. For instance, itcan include an ankle portion 250 and an upper foot element 252 coupledto the ankle portion 250 via an attachment portion 254. The attachmentportion 254 can include or define a bushing or opening through which anaxle extends. An intermediate foot element 256 is disposed generallybelow the upper foot element 252 and attached to the upper foot element252 at a front portion thereof. A lower foot element can be disposedbelow the intermediate foot element. A connection unit 258 can extendbetween the rear of the ankle portion 250 and the rear portion of theintermediate foot element 256. In use, the prosthetic foot 248 canexpand and compress.

The pump system 246 includes a pump mechanism 260 coupled to the ankleportion 250 and an arm member 262 coupled to the attachment portion 254or upper foot element 252. The arm member 262 is arranged to move ordrive the pump mechanism 260 toward at least an expanded configuration(described below) upon movement of the intermediate foot element 256and/or the ankle portion 250 relative to the upper foot element 252. Thepump mechanism 260 includes a housing 264 containing two one-way valveassemblies, a membrane 278, and a connector 280. One of the valveassemblies only allows fluid to enter the pump mechanism 246 and theother only allows fluid to be expelled out of the pump mechanism 260.The connector can be attached to the membrane and the arm member 262 andcan exhibit any suitable configuration. For instance, the connector maybe a fastener or screw.

The housing 264 can include a main portion 270 having a generallycylindrical configuration and a rear portion 272 defining a pair of armsextending from the main portion 270. The rear portion 272 can be securedto the ankle portion 250. A bottom surface of the rear portion 272 cangenerally complete a portion of the front surface of the ankle portion250.

Similar to the previously described pump mechanisms, the pump mechanism260 relies upon deformation of the membrane 278 to move between anoriginal configuration in which the volume of a fluid chamber definedbetween an upper surface of the membrane 278 and the bottom of thehousing 264 is zero or near-zero, and an expanded configuration in whichthe volume of the fluid chamber is increased. The housing 264 isarranged to surround the outer radial edge portion of the membrane 278and creates a seal with the membrane 278. The bottom of the housing 264can define a pair of openings which extend into the housing 264 to forminternal passageways to provide fluid communication between the fluidchamber and the two one-way valve assemblies.

The arm member 262 can comprise a resilient or flexible member having aconfiguration that wraps around a side of the attachment portion 254 tothe front of the attachment portion 254. For instance, the arm member262 defines a first end 274 secured to the side of the attachmentportion 250 via a fastener and a second end 276 attached to theconnector 280.

Operation of the pump system 246 will now be described according to anembodiment. Upon heel strike, the prosthetic foot 248 moves intoexpansion as the ankle portion 150 rotates in a first direction (e.g.,counter-clockwise direction) and the intermediate foot element 256 movesaway from the upper foot element 252. This rotates the pump mechanism260 on the ankle portion 250 away from the attachment portion 254,which, in turn, causes the arm member 262 to exert a force on the pumpmechanism 260. More particularly, this movement of the ankle portion 150and/or the intermediate foot element 256 causes the arm member 262 onthe attachment portion 254 to pull the membrane 278 away from thehousing 270, moving the pump mechanism 260 to the expandedconfiguration.

As the prosthetic foot 248 moves from heel strike through mid-stanceand/or toe-off, the ankle portion 250 rotates in a second direction(e.g., clockwise) and the prosthetic foot 248 moves into compression.This rotates the pump mechanism 260 toward the attachment portion 254and moves the pump mechanism 260 back towards its originalconfiguration. At the end of the stance phase or when the weight of theuser is removed from the prosthetic foot 248, the prosthetic foot 248returns to its resting position and the inherent properties of the armmember 262 help move and/or maintain the pump mechanism 260 in itsoriginal configuration.

It should be appreciated that the pump system 246 can be a separateadd-on module to the prosthetic foot 248. Because of the location andsimple connection of the pump system 246 to the foot, it provides alow-profile design and reduces the likelihood that the pump system 246will interfere with the performance of the foot.

Another embodiment of a prosthetic system 293 comprising a pump system282 and the prosthetic foot 248 is shown in FIG. 15. This embodiment maybe similar to the sixth embodiment except that the pump system 282includes a housing 286 and an arm member 288 having a differentconstruction.

The pump mechanism 282 can be coupled to the ankle portion 250 and thearm member 288 can be coupled to the attachment portion 254 or upperfoot element 252. The housing 286 can include a main portion 290 havinga generally cylindrical configuration and a rear portion 292 defining apair of arms extending from the main portion 290. The rear portion 292can be secured to the ankle portion 250. Each of the arms can have aportion exhibiting a width greater than the main portion 290, creating agap between the bottom surface of the housing 286 and the attachmentportion 254 of the foot 248.

The arm member 288 can comprise a resilient member extending between thefront surface of the attachment portion 254 and a connector 294 of thepump mechanism 282. For instance, the arm member 288 can include a rearend portion including a mounting member 296 attached to the frontsurface of the attachment portion 254 and a front end portion 298defining an opening for attaching the arm member 288 to a membrane 302of the pump mechanism 282.

Operation of the pump system 282 will now be described according to anembodiment. Upon heel strike, the prosthetic foot 248 moves intoexpansion as the ankle portion 150 rotates in a first direction (e.g.,counter-clockwise direction) and the intermediate foot element 256 movesaway from the upper foot element 252. This rotates the pump mechanism282 on the ankle portion 250 away from the attachment portion 254,which, in turn, causes the arm member 288 on the attachment portion 254to pull the membrane 302 away from the housing 286 and drive the pumpmechanism 282 toward the expanded configuration.

As the prosthetic foot 248 moves from heel strike through mid-stanceand/or toe-off, the ankle portion 250 rotates in a second direction(e.g., clockwise) and the prosthetic foot 248 moves into compression.This rotates the pump mechanism 282 toward the attachment portion 154and moves the pump mechanism 282 back towards its originalconfiguration.

Another embodiment of a prosthetic system 301 is shown in FIGS. 16-18.This embodiment can be similar to the previous embodiments described.For instance, the prosthetic system 301 includes a prosthetic foot 302and a pump system 304. The pump system 304 includes a pump mechanism 306and a securing member 308. The pump mechanism 306 is attached to thesecuring member 308 and situated above an upper foot element 310 of theprosthetic foot 302. The pump mechanism 306 is operably connected to anintermediate foot element 312 of the prosthetic foot 302.

Referring to FIGS. 17 and 18, the pump mechanism 306 includes a housing314 containing two one-way valve assemblies 316, 318, a membrane 320(shown in FIG. 16), and a connector 322. The valve assembly 316 onlyallows fluid to enter the pump mechanism 306 which can be in fluidcommunication with the cavity of a socket. The valve assembly 318 onlyallows fluid to be expelled out of the pump mechanism 306, preferably toatmosphere. The connector 322 can be any suitable connector. Forinstance, it can include an upper radial flange embedded in the membrane320, a lower radial flange below the membrane 320, and a shaft portionextending between the upper and lower flanges.

The housing 314 can be coupled to the securing member 308 via at leastone fastener 324 situated at the front portion of the housing 314 andthe securing member 308. The housing 314 can have a rigid configuration.The housing 314 defines a main portion 326, a front portion 328, and arear portion 330 opposite the front portion 328. The front portion 328can have an elongate configuration and extend forwardly over or along anupper surface of the securing member 308.

The rear portion 330 of the housing 314 can be associated with an armmember 332 arranged to move or drive the pump mechanism 306 toward atleast an expanded configuration upon movement of intermediate footelement 312 and/or the ankle portion 250. The arm member 332 can extendgenerally downward from the housing 314 and can be integral to orseparate from the housing 314. In the illustrated embodiment, the armmember 332 can be selectively secured to the rear portion 330 of thehousing 314 via at least one fastener 334 respectively positioned in atleast one fastener hole defined by the arm member 332 and at least onefastener hole defined in the bottom surface of the rear portion 330.Because the arm member 332 can be easily removed from the housing 314and replaced, the length, stiffness, and/or shape of the arm member 332can be advantageously adjustable or customizable without having toreplace the entire housing 314.

The bottom surface of the rear portion 330 can define a keyway 336 and acorresponding key 338 can be defined on an upper surface of the armmember 332. When the arm member 332 is connected to the housing 314, thekey 338 slides into the keyway 336 defined by the housing 314. Thisprevents relative rotation between the arm member 332 and the housing314. It also provides a solid connection between the arm member 332 andthe housing 314 by increasing the contact surface area between the armmember 332 and the housing 314. It further aligns the fastener holes,facilitating assembly and/or disassembly of the pump mechanism 306.

The arm member 332 has an upper head portion for connection to thehousing 314 and a shaft portion extending downwardly from the headportion. The shaft portion has a lower end defining an engagementsurface 341 arranged to engage with an upper surface of the intermediatefoot element 312. The shaft portion of the arm member 332 can include awidth or a cross-sectional area that increases toward the engagementsurface 341, providing a more solid connection between the arm member332 and the intermediate foot element 312.

Similar to the embodiments of the pump mechanism previously described,the pump mechanism 306 relies upon deformation of the membrane 320 tomove between an original configuration in which the volume of a fluidchamber defined between the top surface of the membrane 320 and thebottom of the housing 314 is zero or near-zero, and an expandedconfiguration in which the volume of the fluid chamber is increased. Thehousing 314 can be arranged to surround the outer radial edge portion ofthe membrane 320 and creates a seal with the membrane 320. The bottomsurface of the housing 314 can define a pair of openings which extendinto the housing 314 to form internal passageways, providing fluidcommunication between the fluid chamber and the two one-way valveassemblies 316, 318.

The securing member 308 can include a plate member 340 and a backingportion 342. Optionally, the backing portion 342 and the plate member340 can be made of different materials. For example, the plate member340 can be made of carbon fiber cloth and the backing portion 342 can bemade of metal, plastic, combinations thereof, or any other suitablematerial, facilitating production. Further, because the securing member308 includes a two part construction, the length, curvature, and/orshape of the plate member 340 or backing portion 342 can be beneficiallyadjustable or customizable without having to replace the entire securingmember 308.

The plate member 340 can include a rear portion 344, a front portion346, and a middle portion 348 extending between the rear and frontportions 344, 346. The plate member 340 can have any suitable shape butis shown having a width that tapers from the middle portion 348 towardthe front portion 346 such that the front portion 346 is narrower thanthe middle portion 348.

The front portion 346 can define an aperture for receiving the fastener324 to connect the plate member 340 to the front portion of the housing314. The middle portion 348 can define an aperture for connecting theplate member 340 to the connector 322. A slot or notch 350 is formed inthe terminal edge of the rear portion 344 that allows the arm member 332to extend through the plate member 340 toward the intermediate footelement 312 of the foot 302. The rear portion 344 can define a pair ofapertures on opposing sides of the notch 350.

The backing portion 342 includes a base 352 and a back member 354. Thebottom surface of the base 352 defines a seat 356 arranged toaccommodate the rear portion 344 of the plate member 340 when the platemember 340 is attached to the backing portion 342. This beneficiallylimits or prevents the plate member 340 from sliding sideways off of thebacking portion 342. A slot or notch 358 is defined in the base 352. Theslot 358 can accommodate a portion of the housing 314 and allow the armmember 332 to extend through the base 352.

The base 352 defines a pair of apertures in the seat 356 correspondingto the apertures on the plate member 340 for receiving one or morefasteners 360 to attach the plate member 340 to the backing portion 342.The seat 356 can be in part defined by a pair of side arms 362 definedon the backing portion 342 extending along a portion of the sides of theplate member 340. This helps align the fastener apertures formed in thebase and plate member 340, facilitating assembly.

The back member 354 can extend generally upward from a rear end of thebase 352. The back member 354 can be generally perpendicular to the base352 or oblique relative to the base 352. The back member 354 can definean aperture 362 for receiving a fastener to connect the backing portion342 to the attachment portion 305 or upper foot element of the foot 302.

It should be appreciated that the pump system 304 can include one ormore features for adjusting the sensitivity of the pump mechanism. Forexample, as seen in FIGS. 17 and 18, the aperture 362 can have anelongate configuration for receiving the fastener 364. This allows thefastener 364 to slide up and down within the aperture 362 such that theposition of the pump system 304 relative to the upper foot element 310and/or intermediate foot element 312 can be adjusted before a usertightens the fastener 364 to securely attach the securing member 308 tothe attachment portion of the upper foot element 310.

The height adjustability of the pump system 304 on the attachmentportion 305 can in turn vary the sensitivity of the pump mechanism 306,which may depend on user activity level, weight, and/or other factors.For instance, by adjusting the height of the pump system 304 on theattachment portion 305, the amount and/or period of force applied to thearm member 332 may be adjusted, varying the sensitivity of the pumpmechanism 306 to action of the prosthetic foot 302, advantageouslymaking the pump mechanism 306 customizable to the needs of the user ordesires of a clinician.

In other embodiments, the notch 350 and/or the apertures in the platemember 340 for receiving the connector 322 and the fastener 324 can havean elongate configuration such that the pump mechanism 306 can slideforward and/or backward along the plate member 340 relative to theattachment portion 305. Independent of or in combination with the heightadjustability, this axial or longitudinal adjustability of the pumpsystem 304 along the plate member 340 can vary the sensitivity of thepump mechanism 306. For instance, by moving the pump mechanism 306forwardly toward the front of the foot 302 along the plate member 340,the amount of relative movement between the intermediate foot element312 and the upper foot element 310 required to actuate the pumpmechanism 306 is reduced because of the tapering separation between theintermediate foot element 312 and the upper foot element 310, varyingthe sensitivity of the pump mechanism 306 to action of the foot 302.

According to a variation, the lower end of the arm member 332 caninclude a wedge or tapered shape arranged to more easily advance betweenthe intermediate foot element 312 and the upper foot element 310.

In yet other embodiments, the aperture in the housing 314 for receivingthe fastener 324 can have an elongate configuration similar to theaperture in the plate member 340 such that the distance between the armmember 332 and the connection of the housing 314 to the plate member 340is adjustable. This in turn permits the magnitude of the momentgenerated as the arm member 332 pushes on the housing 314 to beadjusted, varying the sensitivity of the pump mechanism 306.

The rear surface of the back member 354 can generally complement thefront surface of the attachment portion 305. As seen, the rear surfaceof the back member 354 can define one or more grooves 366 arranged toaccommodate one or more projections associated with the attachmentportion 305 as the height of the pump system 304 relative to theintermediate foot element is adjusted.

Optionally, the back member 354 can include one or more alignmentfeatures arranged to help align the securing member 308 on theattachment portion 305. For example, the back member 354 can define apair of opposing members 368 protruding rearwardly from the sides of theback member 354 and arranged to engage or extend along opposing sides ofthe attachment portion 305 when the securing member 308 is positioned onthe attachment portion 305. This beneficially helps align the fasteneraperture 362 on the back member 354 and a fastener aperture on theattachment portion 305, facilitating connection and/or removal of thesecuring member 308 from the foot 302. It also helps limit or preventrelative movement or rotation between the back member 354 and theattachment portion 305.

Another embodiment is shown in FIGS. 19 and 20. This embodiment caninclude a pump mechanism 370 arranged to be operably connected to aprosthetic foot such that action of the prosthetic foot can actuate thepump mechanism 370. The pump mechanism 370 can be a separate add-onmodule to the prosthetic foot.

The pump mechanism 370 can be similar to the previous embodimentsdescribed. For example, the pump mechanism 370 includes a housing 372containing one or more valve assemblies, a membrane 374, and a connector376. The one or more valve assemblies can include a one-way valve, alsoreferred to as a check valve. A preferred type of one-way valve used isa duckbill valve. It should be appreciated however that other types ofone-way valves are possible.

The one or more valve assemblies can include a valve assembly arrangedto only allow fluid to enter the pump mechanism 370. The valve assemblycan be in fluid communication with the cavity of a prosthetic socket.When the volume of the pump mechanism 370 increases, fluid (e.g., air)can be drawn out from the socket via the valve assembly. The one or morevalve assemblies can include another valve assembly arranged to onlyallow fluid to be expelled out of the pump mechanism 370, preferably toatmosphere.

The housing 372 can have a rigid configuration. The housing 372 can haveany shape but is shown having a generally cylindrical shape. The bottomsurface of the housing 372 defines a cavity 378 that is provided with anundercut circumferential groove 380 between an open end of the cavity378 and a closed bottom 382 of the cavity 378. An outer radial edgeportion of the membrane 374 can be situated in the circumferentialgroove 380 such that a seal is formed between the membrane 374 and thehousing 372.

Optionally, an adhesive can be applied between the housing 372 and theouter radial edge portion of the membrane 374, increasing the sealingeffect. The bottom 382 can define two openings which extend into thehousing 372 to form internal passageways providing fluid communicationbetween a fluid chamber defined below and the one or more valveassemblies.

The pump mechanism 370 is movable between an original configuration inwhich the volume of a fluid chamber 384 defined between the top surfaceof the membrane 374 and the bottom 382 of the cavity 378 is zero ornear-zero, and an expanded configuration in which the volume of thefluid chamber 384 is increased. The bottom 382 of the cavity 378 cansubstantially complement the top surface of the membrane 374. Both thebottom 382 of the cavity 378 and the top surface of the membrane 374 canbe generally flat.

The membrane 374 may have any desired shape, but is shown having agenerally circular or elliptical shape. The membrane 374 can beoperatively attached at or near its center to the connector 376 whilethe outer radial edge portion of the membrane 374 is attached to thehousing 372 such that when the connector 376 pulls the membrane awayfrom the housing 372, for example, a pocket forms in a middle area ofthe membrane 374 due to the deformation of the membrane 374. Theformation of the pocket increases the volume of the fluid chamber 384.The pump mechanism 370 thus uses a compliant membrane to create suction.

The connector 376 can have an upper portion 386 embedded in the membrane374, a lower portion 388 below the membrane 374, and a shaft portion 390extending between the upper and lower portions 386, 388. Optionally, theconnector 376 may be of a two-piece construction such that the lowerportion 388 can be threadedly removed from the upper portion 386 in themembrane 374. At least the upper portion 386 of the connector 376 caninclude one or more ferromagnetic materials such as steel, iron, cobalt,or other suitable metal. The upper portion 386 may extend substantiallyinto the membrane 374.

The pump mechanism 370 can include a closure-assist mechanism 392arranged to bias or move the pump mechanism 370 toward its originalconfiguration and/or maintain it therein. In the illustrated embodiment,the closure-assist mechanism 392 comprises a closure element 392 securedwithin a cavity or an opening 394 defined in the bottom 382 of thecavity 378. The closure element 392 can include one or more magneticmaterials such that magnetism can attract or pull the ferromagneticupper portion 386 of the connector 376 toward the bottom 382 of thecavity 378, which, in turn, attracts or pulls the membrane 374 towardthe bottom 382. It will be appreciated that in other embodiments theclosure element 392 can include ferromagnetic materials and theconnector 376 can be a magnet, or both may include magnetic materials.In other embodiments, the closure element 392 can be omitted. Forinstance, the housing 372 may include one or more magnetic materials.

When the connector 376 exerts an expansion or opening force on themembrane 374 sufficient to overcome the closure force between theclosure element 392 and the upper portion 386 of the connector 376, thepump mechanism 370 can move toward the expanded configuration as theexpansion force pulls a portion of the membrane 374 away from the bottom382 of the cavity 378, causing deformation of the membrane 374 and anincrease in volume of the fluid chamber 384. This increase in volume ofthe fluid chamber 384 can draw fluid into the fluid chamber 384 from asocket through the one or more valve assemblies. The housing 372 may beformed of metal such as stainless steel, carbon fiber, plastic or anyother material which would provide sufficient strength to resistdeformation when pulled away from the membrane 374.

Once the expansion force is reduced or removed, the pump mechanism 370returns toward its original configuration as the membrane 374 returnstoward the bottom 382 of the cavity 378 and fluid within the fluidchamber 384 is expelled out of the pump mechanism 370. The closure forcebetween the upper portion 386 of the connector and the closure element392 can move the membrane 374 to its original position on the bottom 382on the cavity 378. This beneficially helps expel fluid from the fluidchamber 384 as its volume is decreased to zero or near-zero. It alsoadvantageously helps maintain the pump mechanism 370 in its originalconfiguration. It can also help maintain the membrane 374 sealed againstthe housing when no force or smaller forces are exerted on the membrane374 by the connector and/or the prosthetic foot. Further, the closureforce can be customized based on the individual needs of the user. Forexample, the magnetic strength of the closure element 392 can beselected to vary the closure force.

Another embodiment is shown in FIGS. 21-23. This embodiment can includea pump mechanism 396 arranged to be operably connected to a prostheticfoot such that action of the prosthetic foot moves the pump mechanism396 between an original configuration and an expanded configuration tocreate an elevated vacuum. The pump mechanism 396 can be a separateadd-on module to the prosthetic foot.

The pump mechanism 396 can be similar to the previous embodimentsdescribed in many respects. For instance, the pump mechanism 396includes a housing 398, a membrane 402, and a connector 404. The housing398 can include at least one valve assembly 406 arranged to only allowfluid to enter the pump mechanism 396 and can be in fluid communicationwith the cavity of a prosthetic socket. The at least one valve assembly406 can include a one-way valve or check valve. A preferred type ofone-way valve used is a duckbill valve however other types of one-wayvalves are possible. When the volume of the pump mechanism 396increases, fluid (e.g., air) can be drawn out from the socket via thevalve assembly 406.

The housing 398 can have a rigid configuration. The housing 398 caninclude an upper member 408 and a base member 410. The upper member 408can have any shape but is shown having a generally cylindrical shapewith a body portion. The bottom surface of the upper member 408 candefine an opening 412 which extends into the upper member 408 to form aninternal passageway providing fluid communication between a fluidchamber defined below and the at least one valve assembly 406.

The membrane 402 is arranged to engage the bottom of the upper member408 such that a seal can be created therebetween. The membrane 402 mayhave any desired shape, but is shown having a generally circularconfiguration. The bottom surface of the membrane 402 can have a contourtapering toward the center.

The pump mechanism 396 is movable between an original configuration inwhich the volume of a fluid chamber 414 defined between the top surfaceof the membrane 402 and the bottom of the upper member 408 is zero ornear-zero, and an expanded configuration in which the volume of thefluid chamber 414 is increased. The bottom of the upper member 408 cansubstantially complement the top surface of the membrane 402. Both thebottom of the upper member 408 and the top surface of the membrane 402can be generally flat.

The connector 404 can have an upper portion 416 embedded in the membrane402 and a shaft portion 418 extending downwardly from the upper portion416. The upper portion 416 may extend substantially into the membrane402. In some embodiments, the connector 404 can include a lower portioncomprising a fastener arranged to be threadedly removable from theconnector 404.

The membrane 402 can be operatively attached at or near its center tothe connector 404. As disclosed in more detail below, when the connector404 pulls the membrane 402 away from the upper member 408 a pocket formsin the middle area of the membrane 402 due to the deformation of themembrane 402. The formation of the pocket increases the volume of thefluid chamber 414. The pump mechanism 396 thus uses a compliant membraneto create suction.

The base member 410 may have any desired shape, but is shown having acircular shape defining an interior opening 420. The outer edge portionof the bottom of the membrane 402 rests on the portion of the basemember 410 surrounding the opening 420 and a center portion of themembrane 402 and the shaft portion 418 are situated within or extendthrough the opening 420. The opening 420 can be dimensioned andconfigured such that the base member 410 does not undesirably interferewith movement of the membrane 402 and connector 404 during operation ofthe pump mechanism 396.

A plurality of connecting portions 422 are circumferentially spacedaround the outer periphery of the base member 410, defining spaces orgaps 430 between the connecting portions 422. Each connecting portion422 includes a generally upright part 424 and a flange part 426extending radially inward from the top of the upright part 424. Theflange part 426 is arranged to extend over and engage an upper surfaceof the upper member 408 such that the membrane 402 can be retained orsecured between the upper member 408 and the base member 410.

When the connector 404 exerts a force on the membrane 402 in a directionaway from the bottom of upper member 408, the pump mechanism 396 movestoward the expanded configuration as the connector 404 pulls a centerportion of the membrane 402 away from the bottom of the upper member 408while the outer edge portion of the membrane 402 remains engaged withthe upper member 408, causing deformation of the membrane 402 and anincrease in the volume of the fluid chamber 414. This increase in volumeof the fluid chamber 414 can draw fluid into the pump mechanism 396through the valve assembly 406.

Once the force is reduced or removed from the membrane, the pumpmechanism 396 can return toward its original configuration as themembrane 402 returns toward the bottom of the upper member 408. Thisclosing movement decreases the volume of the fluid chamber 414, which,in turn, increases the pressure within the fluid chamber 414 until theseal between the upper surface of the membrane 402 and the upper member408 is broken, allowing fluid in the fluid chamber 414 to be expelledout of the sides of the pump mechanism 396 through the gaps 430 betweenthe connecting portions 422. In other words, the fluid in the fluidchamber 414 can escape from between the upper member 408 and themembrane 402 out the side of the housing 398.

The membrane 402 can be elastomeric and can use at least in part itsmaterial properties to naturally or elastically return to its originalposition on the bottom of the upper member 408. It will be appreciatedthat the prosthetic device may include arm or plate operativelyconnected to the prosthetic foot and arranged to bias or force themembrane 402 toward the bottom of the upper member 408, helping to keepthe membrane 402 sealed against the upper member 408. In otherembodiments, the pump mechanism 396 can include a closure-assistmechanism such as a spring or metal clip to bias or help return themembrane 402 toward the bottom of the upper member 408. For instance,the pump mechanism 396 can include a resilient member that engages theupper member 408 and the membrane 402 and/or the connector. Theresilient member biases the membrane 402 toward the bottom of the uppermember 408. The resilient member can comprise a generally u-shapedmember, a torsion spring, a torsion bar, or any other suitable member.

Because the pump mechanism 396 can expel fluid, preferably toatmosphere, without the use of a second valve assembly or a second portin the housing, the pump mechanism 396 is beneficially lighter andeasier to manufacture and maintain. Further, the structure of the pumpmechanism 396 is simpler and helps reduce resistance to air flow out ofthe pump mechanism 396. Moreover, the point at which the buildup ofpressure within the fluid chamber 414 selectively breaks the sealbetween the membrane 402 and the upper member 408 can be any suitablepressure and/or can be customized based on the individual needs of theuser. This pressure can be selected to set by a user, a clinician, or amedical professional.

Another embodiment is shown in FIG. 24. This embodiment can include apump mechanism 432 similar to the pump mechanism 396 except that theupper member is integral to the base member. The pump mechanism 432includes a housing 434 containing a valve assembly 436, a membrane 438,and a connector 440 embedded in part in the membrane 438. The valveassembly 436 is arranged to only allow fluid to enter the pump mechanism432. The housing 434 includes an upper member 442 and a base member 444spaced from the upper member 442.

The membrane 438 can be disposed in the space between the upper member442 and the base member 444 and arranged to engage the bottom of theupper member 442 such that a seal can be formed therebetween. One ormore connecting portions 446 connect the upper member 442 to the basemember 444. The connecting portions 446 can be integral to the uppermember 442 and the base member 444.

In the illustrated embodiment, the upper member 442 can include a firstelongate portion 448 extending radially from a body portion of the uppermember 442 in a first direction and a second elongate portion 450extending radially from the body portion in a second direction. Theelongate portions can advantageously help move the pump mechanism 432between the original and expanded configurations. The base member 444can define an opening 452 arranged to allow a portion of the connector440 and membrane 438 to pass through the base member 444.

The pump mechanism 432 relies upon deformation of the membrane 438 tomove between an original configuration in which the volume of a fluidchamber defined between the top surface of the membrane 438 and thebottom of the upper member 442 is zero or near-zero, and an expandedconfiguration in which the volume of the fluid chamber increases.

In use, when the connector 440 exerts a force on the membrane 438 awayfrom the bottom of the upper member 442, the pump mechanism 432 movestoward the expanded configuration as the volume of a fluid chamberincreases. This increase in volume of the fluid chamber can draw fluidinto the pump mechanism 432 through the valve assembly 436.

Once the force is reduced or removed from the membrane, the pumpmechanism 432 returns toward its original configuration as the membrane438 returns toward the bottom of the upper member 442. This closingmovement decreases the volume of the fluid chamber, which, in turn,increases the pressure in the fluid chamber until the seal between theupper surface of the membrane 438 and the upper member 442 is broken,allowing fluid in the fluid chamber to be expelled out of the sides ofthe pump mechanism 432 between the connecting portions 446.

The base member 444 can include at least one closure-assist featurearranged to help move the pump mechanism 432 toward its originalconfiguration. For instance, the base member 444 can define aclosure-assist mechanism 447 comprising a ring portion 447 having aconical configuration with a free edge portion defining the opening 452,and arranged to bias or force the membrane 438 toward the bottom of theupper member 442. The bottom of the base member 444 can define a recess454 extending around the ring portion 447. This beneficially increasesthe flexibility of the ring portion 447 relative to the remainder of thebase member 444.

As the connector 440 forces the membrane 438 away from the upper member442, the force of the membrane on the ring portion 447 can flex the freeedge portion in a direction away from the upper member 442, storingmechanical energy in the ring portion 447. When the force on themembrane 438 is removed or reduced, the stored energy or resilientproperties of the ring portion 447 can force the free edge portion backtoward the bottom of the upper member 442, which, in turn, moves themembrane 438 toward the bottom of the upper member 442.

This beneficially helps expel fluid from the fluid chamber as its volumeis decreased to zero or near-zero. The closing force of the ring portion447 also advantageously helps maintain the pump mechanism 432 in itsoriginal configuration when no force or smaller forces are exerted onthe membrane 438 by the connector and/or the prosthetic foot. Theclosing force can also help keep the membrane 438 sealed against thebottom of the upper member 442.

Another embodiment of the prosthetic device is shown in FIGS. 25-27.This embodiment can include a pump mechanism 456 arranged to be operablyconnected to a prosthetic foot such that action of the prosthetic footmoves the pump mechanism 456 between an original configuration and anexpanded configuration to create an elevated vacuum.

The pump mechanism 456 can include many of the same features as the pumpmechanism embodiments previously described. For instance, the pumpmechanism 456 includes a housing 458, a membrane 460, and a connector462. In other embodiments, the pump mechanism 456 can include an armmember arranged to move the pump mechanism toward an expandedconfiguration described below.

The housing 458 can include at least one valve assembly 464 arranged toonly allow fluid to enter the pump mechanism 456 and can be in fluidcommunication with the cavity of a prosthetic socket. The at least onevalve assembly 464 can include a one-way valve or check valve. Apreferred type of one-way valve used is a duckbill valve however othertypes of one-way valves are possible. When the volume of the pumpmechanism 456 increases, fluid can be drawn out from the socket via thevalve assembly 464.

The housing 458 can include an upper member 466 and a base member 468.The upper member 466 is shown having a generally cylindrical shape witha body portion but can have any suitable shape. The bottom surface ofthe upper member 466 can define an opening which extends into the uppermember 466 to form an internal passageway providing fluid communicationbetween a fluid chamber defined below and the at least one valveassembly 464.

The membrane 460 is arranged to engage the bottom of the upper member466 such that a seal can be formed therebetween. The membrane 460 mayhave any suitable shape. For instance, the membrane 460 can be generallycylindrical with a lower conical contour.

Similar to the other embodiments, the pump mechanism 456 is movablebetween an original configuration in which the volume of a fluid chamber470 defined between the top surface of the membrane 460 and the bottomof the upper member 466 is zero or near-zero, and an expandedconfiguration in which the volume of the fluid chamber 470 is increased.The bottom of the upper member 466 can substantially complement the topsurface of the membrane 460 and is arranged to form a seal between theupper member 466 and the membrane 460. Both the bottom of the uppermember 466 and the top surface of the membrane 460 can be generallyflat.

As seen, the connector 462 can include an upper portion 472 embedded inthe membrane 460 and a shaft portion 474 extending downwardly from theupper portion 472. The upper portion 472 may extend substantially intothe membrane 460. Optionally, the connector 462 can include a lowerportion comprising a fastener arranged to be threadedly removable fromthe connector 462.

The connector 462 can be attached at or near a center of the membrane460. As described in more detail below, when the connector 462 pulls themembrane 460 away from the upper member 466 a pocket forms in the centeror middle area of the membrane 460 due to the deformation of themembrane 460. The formation of the pocket increases the volume of thefluid chamber 470. The pump mechanism 456 thus uses a compliant membraneto create suction.

The base member 468 can include an open cavity 476 having a peripheralinternal wall. The cavity 476 may have any desired shape, but is shownhaving a generally cylindrical shape. The cavity 476 is arranged so thatthe top opening is located at or near the top of the base member 468 anda closed bottom 478 located at or near the bottom of the bottom of thebase member 468. An aperture 480 can be defined in the closed bottom478, arranged to allow the lower portion of the connector 462 to extendthrough the bottom 478.

The cavity 476 can include an upper cavity area adjacent to the topopening and a lower cavity area located towards the closed bottom. Theupper and lower cavity areas can be generally concentric. The basemember 468 can be formed of any of the materials previously described.

The upper cavity area can define an undercut circumferential groove 482in the peripheral internal wall between the top opening and the lowercavity area. An outer radial edge portion of the membrane 460 and theupper member 466 can be situated in the circumferential groove 482 suchthat the membrane 460 and upper member 466 are secured within the cavity476. The base member 468 can define a plurality of ports or throughholes 484 within the circumferential groove 482. The through holes 484can allow fluid to be expelled from the pump mechanism 456 toatmosphere.

The lower cavity area can include a closure-assist mechanism comprisinga plurality of resilient elements 486 defining peaks and valleys or awavy profile. The resilient elements 486 can be generally concentricwith varying heights. The resilient elements 486 can support a bottom ofthe membrane 460 within the cavity 476 and can help bias and/or move thepump mechanism 456 toward the original configuration.

For instance, when the connector 462 exerts a force on the membrane 460in a direction away from the bottom of the upper member 466, the pumpmechanism 456 moves toward the expanded configuration as the connector462 pulls a center portion of the membrane 460 away from the bottom ofthe upper member 466 while the outer radial edge portion remains engagedwith the upper member 466, causing deformation of the membrane 460 andan increase in the volume of the fluid chamber 470. This increase in thevolume of the fluid chamber 470 can draw fluid into the pump mechanism456 through the valve assembly 464.

The downward movement of the membrane 460 also forces the bottom 478 ofthe cavity 476 away from the bottom of the upper member 466, causing theresilient elements 486 to flex (e.g., the resilient elements 486 can bein compression and/or tension) and store mechanical energy.

Once the force from the connector 462 is reduced or removed from themembrane 460, the stored mechanical energy in the resilient elements 486can bias or force the membrane back toward the bottom of the uppermember 466, moving the pump mechanism 456 toward its originalconfiguration. This forced closure decreases the volume of the fluidchamber 470, which, in turn, increases the pressure on the fluid withinthe fluid chamber 470 until the seal between the upper surface of themembrane 460 and the upper member 466 is broken. This allows the fluidto be expelled out of the pump mechanism 456 through the through holes484 and/or out of the top opening of the cavity 476. The closure forceof the resilient elements 486 can also help keep the membrane 460 sealedagainst the bottom of the upper member 466.

Because the pump mechanism 456 can expel fluid, preferably toatmosphere, without the use of a second valve assembly, the pumpmechanism 456 is beneficially lighter and easier to manufacture andmaintain. Further, the closure force of the resilient elements 486 canbe customized based on the individual needs of the user. For instance,the resilient elements 486 can be dimensioned and/or formed of selectedmaterials to vary the closure force.

Another embodiment is shown in FIG. 27. This embodiment can include apump mechanism 490 similar to the previously describe pump mechanismembodiments. The pump mechanism 490 includes a housing 492 containing avalve assembly 494, a membrane, and a connector. The valve assembly 494only allows fluid to enter the pump mechanism 490 which can be in fluidcommunication with the cavity of a socket. An arm member 496 including apair of bar members can be attached to the housing 492, and connectedtogether a distance from the housing 492. Each bar can include a firstportion extending from the housing 492 and a second portion curvingdownwardly from the first portion. The arm member 496 can engage aportion of a prosthetic foot to move the pump mechanism 490 as describedherein.

The pump mechanism 490 relies upon deformation of the membrane to movebetween an original configuration in which the volume of a fluid chamberdefined between the top surface of the membrane and the bottom of thehousing 492 is zero or near-zero, and an expanded configuration in whichthe volume of the fluid chamber is increased. The housing 492 isarranged to surround the outer radial edge portion of the membrane andcreates a seal with the membrane. The bottom surface of the housing 492can define an opening which extends into the housing 492 to form aninternal passageway to provide fluid communication between the fluidchamber and the valve assembly 494. An aperture or outlet 498 is definedin the housing 492 to provide fluid communication between the fluidchamber and preferably atmosphere.

When a force is exerted on the membrane away from the housing 492, thepump mechanism 490 moves toward the expanded configuration as the volumeof the fluid chamber increases. This volume increase can draw fluid intothe pump mechanism 490 through the valve assembly 494.

Once the force is reduced or removed from the membrane, the pumpmechanism 490 returns toward its original configuration as the membranereturns toward the bottom of the housing 492. This closing movementdecreases the volume of the fluid chamber, which, in turn, increases thepressure in the fluid chamber until the seal between the membrane andthe housing 492 is broken, allowing fluid in the fluid chamber to beexpelled out of the outlet 498. The pump mechanism 490 is beneficiallylighter or easier to make. Similar to the other embodiments, the pumpmechanism 490 can include a closure-assist mechanism arranged to helpmove or maintain the pump mechanism 490 in its original configuration.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments are contemplated. For instance, the membraneused in the embodiments described can vary in thickness in differentareas and in shape. The thickness of the membrane may be thicker at theportions attached to the rigid wall to create a stronger connection andgreater deformation of the membrane wall. Similarly, the membrane wallmay be thinner than the attachment portions to allow for greaterdisplacement with less force. The membrane may be a cylindrical shape, atapered shape, or any other suitable shape. In other embodiments, thepump mechanism can include a plurality of closure-assist mechanisms suchas a magnetic closure element and a resilient closure element.

In other embodiments, the pump system can be arranged to move the pumpmechanism from its original configuration to its expanded configurationupon expansion of the prosthetic foot or heel strike. In otherembodiments, the pump mechanism can move from its original configurationto its expanded configuration upon heel strike and/or toe-off. It shouldbe appreciated that embodiments of the pump system described herein canbe coupled to any suitable prosthetic foot. For instance, theembodiments of the foot system can be coupled to the prosthetic footdescribed in U.S. patent application Ser. No. 13/309,418, filed on Dec.1, 2011, and commercially available as the XC VARI-FLEX by Össur hf.This disclosure is incorporated by reference and belongs to the assigneeof this disclosure.

The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting. Additionally, thewords “including,” “having,” and variants thereof (e.g., “includes” and“has”) as used herein, including the claims, shall be open ended andhave the same meaning as the word “comprising” and variants thereof(e.g., “comprise” and “comprises”).

1. A prosthetic system comprising: a prosthetic foot including an upperfoot element having a concave-forward facing portion and a foot portionextending forwardly therefrom, an intermediate foot element disposedbelow the upper foot element and having a front portion coupled to thefoot portion of the upper foot element, and a lower foot elementdisposed below the intermediate foot element, wherein the upper footelement and the intermediate foot element are movable relative to oneanother upon movement of the prosthetic foot; and a pump system coupledto the prosthetic foot and comprising: a pump mechanism including ahousing defining a cavity and a membrane situated in the cavity, thepump mechanism being movable between an original configuration in whichthe volume of a fluid chamber defined between the membrane and a bottomof the cavity is zero or near-zero, and an expanded configuration inwhich the volume of the fluid chamber is increased; and an arm memberextending from the pump mechanism and operatively coupled to theintermediate foot element, the arm member arranged to move the pumpmechanism toward at least the expanded configuration upon movement ofthe intermediate foot element relative to the upper foot element.
 2. Theprosthetic system of claim 1, wherein the arm member is selectivelyengageable with an upper surface of the intermediate foot element andhas a rigid configuration.
 3. The prosthetic system of claim 1, whereina distance between the pump mechanism and the intermediate foot elementis adjustable to vary sensitivity of the pump mechanism.
 4. Theprosthetic system of claim 1, wherein a distance between a portion ofthe pump system and the upper foot element is adjustable to varysensitivity of the pump mechanism.
 5. The prosthetic system of claim 2,wherein the arm member comprises an elongate member defined by thehousing and extending downwardly through an opening defined in the upperfoot element and toward the intermediate foot element.
 6. The prostheticsystem of claim 5, wherein the elongate member defines a widthincreasing in a direction toward the intermediate foot element.
 7. Theprosthetic system of claim 5, wherein the elongate member defines a keyarranged to fit in a corresponding keyway defined by the housing.
 8. Theprosthetic system of claim 1, wherein the arm member includes two armsextending along each side of the upper foot element to a rear endportion of the intermediate foot element.
 9. The prosthetic system ofclaim 1, wherein the housing includes a main portion, a front portion,and a width that tapers from the main portion toward the front portionof the housing.
 10. The prosthetic system of claim 9, wherein flexion ofthe housing at the front portion allows the pump mechanism to movebetween the original configuration and the expanded configuration. 11.The prosthetic system of claim 1, further comprising: an ankle portionrotatable attached to the upper foot element; and a connection unitconnected to a rear portion of the ankle portion and a rear end portionof the intermediate foot element, the connection unit being arranged tomove and upper and intermediate foot elements relative to one another.12. The prosthetic system of claim 11, wherein rotation of the ankleportion in a first direction causes the connection unit to pull the rearend portion of the intermediate foot element toward the upper footelement.
 13. The prosthetic system of claim 12, wherein rotation of theankle portion in a second direction causes the connection unit to forcethe rear end portion of the intermediate foot element away from theupper foot element.
 14. The prosthetic system of claim 1, wherein thepump mechanism includes a closure-assist mechanism arranged to bias thepump mechanism toward the closed configuration.
 15. The prostheticsystem of claim 14, wherein the closure-assist mechanism comprises aclosure element having one or more magnetic materials.
 16. A prostheticsystem comprising: a prosthetic foot including an upper foot elementhaving a concave-forward facing portion and a foot portion extendingforwardly therefrom, an intermediate foot element disposed below theupper foot element and having a front portion coupled to the footportion of the upper foot element, and a lower foot element disposedbelow the intermediate foot element, wherein the upper foot element andthe intermediate foot element are movable relative to one another uponmovement of the prosthetic foot; a pump system coupled to the prostheticfoot and comprising: a pump mechanism including a housing defining acavity and a membrane situated in the cavity, the pump mechanism beingmovable between an original configuration in which the volume of a fluidchamber defined between the membrane and a bottom of the cavity is zeroor near-zero, and an expanded configuration in which the volume of thefluid chamber is increased; and an arm member extending from the pumpmechanism and arranged to move the pump mechanism toward the expandedconfiguration upon engagement with the intermediate foot element andmovement of the intermediate foot element toward to the upper footelement; and a prosthetic socket in fluid communication with the pumpmechanism and connected to the prosthetic foot.
 17. The prostheticsystem of claim 16, wherein the arm member comprises an elongate andrigid member defined by the housing and extending downwardly through anopening defined in the upper foot element and toward the intermediatefoot element.
 18. The prosthetic system of claim 16, wherein the armmember has a resilient configuration.
 19. A prosthetic systemcomprising: a prosthetic foot; a pump system is coupled to theprosthetic foot and comprises a pump mechanism including a housingdefining a cavity and a membrane situated in the cavity, the pumpmechanism movable between an original configuration in which the volumeof a fluid chamber defined between the membrane and a bottom of thecavity is zero or near-zero, and an expanded configuration in which thevolume of the fluid chamber is increased; and a closure-assist mechanismintegrated with the cavity of the pump mechanism and arranged to biasthe pump mechanism toward the original configuration.
 20. The prostheticsystem of claim 19, wherein the closure-assist mechanism comprises aplurality of resilient elements defined by the housing.